Dresden 2026 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 8: Nanostructures at surfaces:1D, 2D, networks I
O 8.2: Vortrag
Montag, 9. März 2026, 10:45–11:00, WILL/A317
On-surface prepared 2D MOFs as models of single-atom catalysts: Fe-N3 vs. Fe-N4 — •Zdeněk Jakub1, Jakub Planer1, Dominik Hrůza1, Ayesha Jabeen1, Tadeáš Lesovský1, and Jan Čechal1,2 — 1CEITEC, Brno University of Technology, Brno, Czechia — 2Faculty of Mechanical Engineering, Brno University of Technology, Brno, Czechia
What defines the reactivity of the so-called single-atom catalysts? Here, we utilize 2D Metal-Organic Frameworks (MOFs) synthesized on an inert graphene support to address this fundamental question. By temperature-dependent scanning tunneling microscopy and density functional theory, we quantify the CO adsorption strengths on threefold-coordinated (Fe-N3) and fourfold-coordinated (Fe-N4) iron sites embedded within Fe-DCA and Fe-TCNQ 2D MOFs. A significant 0.5 eV difference in CO binding strengths is found, despite the fact that the electronic parameters like Fe oxidation state, spin configuration, occupancy of the individual d-orbitals and their positions with respect to Fermi level are almost identical prior to CO adsorption. We trace the origin of the different reactivity to the higher structural flexibility of the Fe-N3 sites compared to Fe-N4. These results highlight the key role of local coordination and demonstrate that reactivity cannot be reliably predicted from electronic structure parameters alone.
Keywords: 2D Metal-Organic Frameworks; Reactivity; Adsorption; Scanning Tunneling Microscopy; Single-Atom Catalysis